It's the basement apartment like no other. Life has been found 1.6 kilometres beneath the sea floor, at temperatures reaching 100 °C. The discovery marks the deepest living cells ever to be found beneath the sea floor. Bacteria have been found deeper underneath the continents, but there they are rare. In comparison, the rocks beneath the sea appear to be teeming with life. John Parkes, a geobiologist at the University of Cardiff, UK, hopes his team's discovery might one day help find life on other planets. He says it might even redefine what we understand as life, and, bizarrely, what...